A typical selectable one-way clutch (SOWC) is designed to have only two modes of operation; namely, a forward mode, wherein the input race is free to rotate with respect to the output race, and reverse mode, wherein the input race is mechanically locked to the output race in at least one direction of rotation. SOWC's are used in automatic transmissions to facilitate shifting from forward to reverse, replacing both a one-way clutch and a plate clutch. A forward/reverse selection mechanism for these types of SOWC's is typically either hydraulically or electrically controlled. In these types of SOWC's, movement of a slide plate or ring in the SOWC controls strut movement to lock and unlock an input race with respect to an output race. Normally, when the slide plate covers the reverse struts, the SOWC is in the forward mode, which is commonly the default mode.
Other SOWC's have provided three modes of operation that include a neutral mode, in addition to forward and reverse modes. In these SOWC's, the forward and reverse struts may be separate or they may be integrated into a single strut. When a reverse strut or a reverse portion of the single strut is covered by the slide plate, the SOWC transmits torque, or “holds”, in the forward direction of rotation and freewheels in the opposite, or reverse direction. When a forward strut or a forward portion of the single strut is covered by the slide plate, the SOWC transmits torque, or “holds” in the reverse direction of rotation and freewheels in the opposite, or forward direction. A plurality of actuators is typically used to move the slide plate between the desired positions.